do you have a big window in a room that faces east? if so then i would just use natural light early in the morning. bit of a photo geak myself and any time i used flash when my daughter was young then she woudl get shocked adn cry a bit or wake her up.
the thinkg that makes the most difference are the props, all teh cool baby pics i have seen are the babies on really cosy looking blankets or funny little cute hats etc…
other tips i learnt, super heat the room so that it is nearly unbearable, it sends them to sleep easily and makes them easy to move about, fill them up with milk as well just before. if you want them ‘au naturel’ have a few blankets around to catch any accidents and alos take the nappy off a bit before so there are no pressur eline sin the skin.
it took me three different attempts before i go pictures that i liked.
and congrats on being a dad.